From: Boaz Harrosh If we export scsi_init_io()/scsi_release_buffers() instead of scsi_{alloc,free}_sgtable() from scsi_lib than tgt code is much more insulated from scsi_lib changes. As a bonus it will also gain bidi capability when it comes. Signed-off-by: Boaz Harrosh Acked-by: FUJITA Tomonori Signed-off-by: Andrew Morton --- drivers/scsi/scsi_lib.c | 21 ++++++++++----------- drivers/scsi/scsi_tgt_lib.c | 34 +++++----------------------------- include/scsi/scsi_cmnd.h | 4 ++-- 3 files changed, 17 insertions(+), 42 deletions(-) diff -puN drivers/scsi/scsi_lib.c~bidi-support-tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable drivers/scsi/scsi_lib.c --- a/drivers/scsi/scsi_lib.c~bidi-support-tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable +++ a/drivers/scsi/scsi_lib.c @@ -739,7 +739,8 @@ static inline unsigned int scsi_sgtable_ return index; } -struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) +static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, + gfp_t gfp_mask) { struct scsi_host_sg_pool *sgp; struct scatterlist *sgl, *prev, *ret; @@ -825,9 +826,7 @@ enomem: return NULL; } -EXPORT_SYMBOL(scsi_alloc_sgtable); - -void scsi_free_sgtable(struct scsi_cmnd *cmd) +static void scsi_free_sgtable(struct scsi_cmnd *cmd) { struct scatterlist *sgl = cmd->request_buffer; struct scsi_host_sg_pool *sgp; @@ -873,8 +872,6 @@ void scsi_free_sgtable(struct scsi_cmnd mempool_free(sgl, sgp->pool); } -EXPORT_SYMBOL(scsi_free_sgtable); - /* * Function: scsi_release_buffers() * @@ -892,7 +889,7 @@ EXPORT_SYMBOL(scsi_free_sgtable); * the scatter-gather table, and potentially any bounce * buffers. */ -static void scsi_release_buffers(struct scsi_cmnd *cmd) +void scsi_release_buffers(struct scsi_cmnd *cmd) { if (cmd->use_sg) scsi_free_sgtable(cmd); @@ -904,6 +901,7 @@ static void scsi_release_buffers(struct cmd->request_buffer = NULL; cmd->request_bufflen = 0; } +EXPORT_SYMBOL(scsi_release_buffers); /* * Function: scsi_io_completion() @@ -1106,7 +1104,7 @@ void scsi_io_completion(struct scsi_cmnd * BLKPREP_DEFER if the failure is retryable * BLKPREP_KILL if the failure is fatal */ -static int scsi_init_io(struct scsi_cmnd *cmd) +int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) { struct request *req = cmd->request; int count; @@ -1121,7 +1119,7 @@ static int scsi_init_io(struct scsi_cmnd /* * If sg table allocation fails, requeue request later. */ - cmd->request_buffer = scsi_alloc_sgtable(cmd, GFP_ATOMIC); + cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask); if (unlikely(!cmd->request_buffer)) { scsi_unprep_request(req); return BLKPREP_DEFER; @@ -1150,6 +1148,7 @@ static int scsi_init_io(struct scsi_cmnd return BLKPREP_KILL; } +EXPORT_SYMBOL(scsi_init_io); static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, struct request *req) @@ -1195,7 +1194,7 @@ int scsi_setup_blk_pc_cmnd(struct scsi_d BUG_ON(!req->nr_phys_segments); - ret = scsi_init_io(cmd); + ret = scsi_init_io(cmd, GFP_ATOMIC); if (unlikely(ret)) return ret; } else { @@ -1246,7 +1245,7 @@ int scsi_setup_fs_cmnd(struct scsi_devic if (unlikely(!cmd)) return BLKPREP_DEFER; - return scsi_init_io(cmd); + return scsi_init_io(cmd, GFP_ATOMIC); } EXPORT_SYMBOL(scsi_setup_fs_cmnd); diff -puN drivers/scsi/scsi_tgt_lib.c~bidi-support-tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable drivers/scsi/scsi_tgt_lib.c --- a/drivers/scsi/scsi_tgt_lib.c~bidi-support-tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable +++ a/drivers/scsi/scsi_tgt_lib.c @@ -331,8 +331,7 @@ static void scsi_tgt_cmd_done(struct scs scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag); - if (scsi_sglist(cmd)) - scsi_free_sgtable(cmd); + scsi_release_buffers(cmd); queue_work(scsi_tgtd, &tcmd->work); } @@ -353,31 +352,6 @@ static int scsi_tgt_transfer_response(st return 0; } -static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask) -{ - struct request *rq = cmd->request; - int count; - - cmd->use_sg = rq->nr_phys_segments; - cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask); - if (!cmd->request_buffer) - return -ENOMEM; - - cmd->request_bufflen = rq->data_len; - - dprintk("cmd %p cnt %d %lu\n", cmd, scsi_sg_count(cmd), - rq_data_dir(rq)); - count = blk_rq_map_sg(rq->q, rq, scsi_sglist(cmd)); - if (likely(count <= scsi_sg_count(cmd))) { - cmd->use_sg = count; - return 0; - } - - eprintk("cmd %p cnt %d\n", cmd, scsi_sg_count(cmd)); - scsi_free_sgtable(cmd); - return -EINVAL; -} - /* TODO: test this crap and replace bio_map_user with new interface maybe */ static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd, unsigned long uaddr, unsigned int len, int rw) @@ -403,9 +377,11 @@ static int scsi_map_user_pages(struct sc } tcmd->bio = rq->bio; - err = scsi_tgt_init_cmd(cmd, GFP_KERNEL); - if (err) + err = scsi_init_io(cmd, GFP_KERNEL); + if (err) { + scsi_release_buffers(cmd); goto unmap_rq; + } return 0; diff -puN include/scsi/scsi_cmnd.h~bidi-support-tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable include/scsi/scsi_cmnd.h --- a/include/scsi/scsi_cmnd.h~bidi-support-tgt-use-scsi_init_io-instead-of-scsi_alloc_sgtable +++ a/include/scsi/scsi_cmnd.h @@ -128,8 +128,8 @@ extern void *scsi_kmap_atomic_sg(struct size_t *offset, size_t *len); extern void scsi_kunmap_atomic_sg(void *virt); -extern struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t); -extern void scsi_free_sgtable(struct scsi_cmnd *); +extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask); +extern void scsi_release_buffers(struct scsi_cmnd *cmd); extern int scsi_dma_map(struct scsi_cmnd *cmd); extern void scsi_dma_unmap(struct scsi_cmnd *cmd); _